The webcam become more and more popular, its quality is getting better and the price is much cheaper. This paper’s architecture comprise of two parts: Webcam and personal computer. To substitute for tradition mouse and keyboard as input we using the skin color as a tracing target. Because of the modern people are very busy, they can’t spare any time to do exercise. And this reason cause general problem of fat. To solve the problem we design a game for human machine interface device and this game can let people do exercise at home all you have to do is face the screen and enjoy it.